Dispersant additives and process

ABSTRACT

The invention pertains to improved lubricating oil dispersants wherein a fractionating polymer is prepared prior to functionalization (e.g., in the Koch reaction) for making dispersant additives. In one aspect, it was discovered that by fractionating a polymer to remove light hydrocarbon and unreacted monomer from the polymer before the carbonylation step of the Koch reaction, the amount of light ester impurities generated was minimized. Light ester is an undesirable byproduct that adversely affects the recycle of the catalyst from the functionalization step of the Koch reaction. The invention also pertains to improved lubricating oil nitrogen-containing dispersant additives derived from fractionated polymer.

This is a divisional of application Ser. No. 579,317, filed Dec. 27,1995 abandoned which is a Continuation-in-part of U.S. Ser. No.08/261,557, filed Jun. 17, 1994.

The present invention relates to dispersant additives and processes fortheir preparation, and is particularly directed to an improveddispersant additive obtained via the Koch reaction and a process forpreparing the same. The Koch reaction relates to reacting at least onecarbon--carbon double bond with carbon monoxide in the presence of anacidic catalyst and a nucleophilic trapping agent to form a carbonyl- orthiocarbonyl-containing functional group, such as a carboxylic acid or acarboxylic ester functional group. Koch-based dispersants includederivatives of the Koch reaction product.

The term "polymer" is used herein to refer to materials comprising largemolecules built up by the repetition of small, simple chemical units. Ina hydrocarbon polymer those units are predominantly formed of hydrogenand carbon. Polymers are defined by average properties, and in thecontext of the invention polymers have a number average molecular weight(M_(n)) of at least 500. Light polymer used herein refers to polymerhaving less than 300 molecular weight (e.g., 48 to 288). Deeper cutpolymers herein refer to polymers having less than 500 molecular weight(e.g., 48 to 490). The term "raw polymer" is herein intended to refer topolymer as manufactured containing the above described light polymer anddeeper cut polymers.

The term "hydrocarbon" is used herein to refer to non polymericcompounds comprising hydrogen and carbon having uniform properties suchas molecular weight. However, the term "hydrocarbon" is not intended toexclude mixtures of such compounds which individually are characterizedby such uniform properties. Light hydrocarbon as used herein refers tocompounds having a carbon number between C₄ and C₂₄, inclusive.

U.S. Ser. No. Attorney Docket Number PT-1241, filed Nov. 28, 1995,Amidation of Ester Functionalized Polymers, which is a continuation ofU.S. Ser. No. 261,507, filed Jun. 17, 1994, abandoned; U.S. Ser. No.261,559, filed Jun. 17, 1994, Batch Koch Carbonylation Process; U.S.Ser. No. 261,534, filed Jun. 17, 1994, Derivatives of Polyamines WithOne Primary Amine and Secondary or Tertiary Amines; U.S. Ser. No.261,560, filed Jun. 17, 1994, Continuous Process for Production ofFunctionalized Olefins; U.S. Ser. No. 261,554, filed Jun. 17, 1994,Lubricating Oil Dispersants Derived from Heavy Polyamines; and U.S. Ser.No. 261,558, filed Jun. 17, 1994, Functionalized Additives Useful InTwo-Cycle Engines, all contain related subject matter as indicated bytheir titles and are hereby incorporated by reference in their entiretyfor all purposes.

U.S. Ser. No. 534,891, filed Sep. 25, 1995, which is a continuation ofU.S. Ser. No. 992,403, filed Dec. 17, 1992, abandoned, and which isincorporated by reference herein discloses reactions of a polymer havingat least one ethylenic double bond reacted via a Koch mechanism to formcarbonyl or thio carbonyl group-containing compounds which maysubsequently be derivatized. The polymers react with carbon monoxide inthe presence of an acid catalyst or a catalyst preferably complexed withthe nucleophilic trapping agent. A preferred catalyst is BF₃ andpreferred catalyst complexes include BF₃.H₂ O and BF₃ complexed withhalo-substituted phenols. The starting polymer reacts with carbonmonoxide at point of unsaturation to form either iso- or neo-acyl groupswith the nucleophilic trapping agent, e.g., with water, alcohol(preferably a substituted phenol) or thiol to form respectively acarboxylic acid, carboxylic ester group, or thio ester.

The functionalized polymer can be subsequently derivatized with interalia an amine, alcohol, amino alcohol, etc. to form a dispersantadditive for lubricant applications.

The present invention relates to fractionating (e.g., stripping) rawpolymer to remove at least the light polymers or alternatively lighthydrocarbon from the raw polymer prior to the reaction described above.The removal of the light polymer fraction results in a surprisingreduction in the amount of heretofore unwanted byproducts, such as lightpolymer esters formed during the Koch reaction. The removal of thedeeper cut polymer fraction results in a fractionated polymer whichallows a lubricating oil additive to be made of surprisingly improveddispersant properties.

The presence of light polymer ester can adversely affect the performanceof the final dispersant product. Furthermore, nitrogen-containingderivatives (e.g., amine derivatives) of the Koch functionalizedpolymers formed from the fractionated polymer exhibit unexpectedlyimproved dispersancy. Hence, it is desirable to eliminate or minimizethe content of light polymer present in the Koch reaction.

The presence of light functionalized polymer (e.g., polymer ester) has asecond deleterious effect on the process described above. In oneembodiment of the process, the functionalized fractionated polymer mustbe treated prior to the derivatization step. The crude ester produced inthe carbonylation contains inter alia the functionalized fractionatedpolymer, impurities, and in the case of the use of the preferrednucleophilic trapping agent, unreacted halophenol (e.g.,2,4-dichlorophenol). Using, for example, evaporation, the functionalizedfractionated polymer is further treated to remove the unreactedhalophenol. The distillate is collected and fractionally distilled torecover and recycle the unreacted halophenol. However, some of theimpurities, especially the light polymer esters that boil close tohalophenol as well as light halogenated compounds are also inadvertentlyrecycled. In a continuous process, such as in a commercial facility, therecycle stream of desired unreacted halophenol will be quickly saturatedwith the undesirable components, such as the light esters.

Since the evaporation is a single stage operation, an equilibrium levelof undesirable components (e.g., light esters) will build up in theprocess stream. In order to maintain low impurity levels the distillatemay have to be purged (e.g., discarded). This is very costly from thestandpoint of the loss of valuable chemicals but also from anenvironmental standpoint. Thus, it is very desirable to minimize theamount of light ester present in the crude ester fed to the evaporators.This is accomplished by minimizing the introduction of light esterprecursors such as C₄ to C₂₄ olefins in the fractionated polymer feed tothe functionalization process.

BACKGROUND OF THE INVENTION

Both hydrocarbon compounds, as well as polymeric compounds, have beenreacted to form carboxyl group-containing compounds and theirderivatives.

Carboxyl groups have the general formula --CO--OR, where R can be H, ahydrocarbyl group, or a substituted hydrocarbyl group.

The synthesis of carboxyl group-containing compounds from olefinichydrocarbon compounds, carbon monoxide, and water in the presence ofmetal carboxyls is disclosed in references such as N. Bahrmann, Chapter5, Koch Reactions, "New Synthesis with Carbon Monoxide" J. Falbe;Springer-Verlag, New York, 1980. Hydrocarbons having olefinic doublebonds react in two steps to form carboxylic acid-containing compounds.In the first step an olefin compound reacts with an acid catalyst andcarbon monoxide in the absence of water. This is followed by a secondstep in which the intermediate formed during the first step undergoeshydrolysis or alcoholysis to form a carboxylic acid or ester. Anadvantage of the Koch reaction is that it can occur at moderatetemperatures of -20° C. to +80° C., and pressures up to 100 bar.

The Koch reaction can occur at double bonds where at least one carbon ofthe double bond is di-substituted to form a "neo" acid or ester ##STR1##

The Koch reaction can also occur when both carbons are mono-substitutedor one is monosubstituted and one is unsubstituted to form an "iso" acid(i.e. --R'HC--COOR). Bahrmann et al. discloses isobutylene converted toisobutyric acid via a Koch-type reaction.

U.S. Pat. No. 2,831,877 discloses a multi-phase, acid catalyzed,two-step process for the carboxylation of olefins with carbon monoxide.

Complexes of mineral acids in water with BF₃ have been studied tocarboxylate olefins. U.S. Pat. No. 3,349,107 discloses processes whichuse less than a stoichiometric amount of acid as a catalyst. Examples ofsuch complexes are H₂ O.BF₃.H₂ O, H₃ PO₄.BF₃.H₂ O and HF.BF₃.H₂ O.

EP-A-0148592 relates to the production of carboxylic acid esters and/orcarboxylic acids by catalyzed reaction of a polymer havingcarbon--carbon double bonds, carbon monoxide and either water or analcohol, optionally in the presence of oxygen. The catalysts are metalssuch as palladium, rhodium, ruthenium, iridium, and cobalt incombination with a copper compound, in the presence of a protonic acidsuch as hydrochloric acid. A preferred polymer is polyisobutene, whichmay have at least 80% of its carbon--carbon double bonds in the form ofterminal double bonds. Liquid polyisobutene having a number averagemolecular weight in the range of from 200 to 2,500, preferably up to1,000 are described.

U.S. Pat. No. 4,927,892 relates to reacting a polymer or copolymer of aconjugated diene, at least part of which is formed by 1,2polymerization, with carbon monoxide and water and/or alcohol in thepresence of a catalyst prepared by combining a palladium compound,certain ligands and/or acid except hydrohalogenic acids having a pKa ofless than 2. Useful Lewis acids include BF₃.

Although there are disclosures in the art of olefinic hydrocarbonsfunctionalized at the carbon--carbon double bond to form a carboxylicacid or derivative thereof via Koch-type chemistry, there is nodisclosure that polymers containing carbon--carbon double bonds,including terminal olefinic bonds, either secondary or tertiary typeolefinic bonds, could be successfully reacted via the Koch mechanism.The Koch process is particularly useful to make neo acid and neo esterfunctionalized polymer. The present invention is useful to improve theKoch process. Known catalysts used to carboxylate low molecular weightolefinic hydrocarbons by the Koch mechanism were found to be unsuitablefor use with polymeric material. Specific catalysts have been foundwhich can result in the formation of a carboxylic acid or ester at acarbon--carbon double bond of a polymer. Koch chemistry affords theadvantage of the use of moderate temperatures and pressures, by usinghighly acidic catalysts and/or careful control of concentrations.

SUMMARY OF THE INVENTION

In one aspect, the present invention is a process for improving apolymer used in the Koch reaction for making dispersant additivescomprising: fractionating a polymer to remove a light hydrocarbonfraction prior to the carbonylation step. The present invention is alsoa functionalized, fractionated hydrocarbon polymer wherein thefractionated polymer backbone has M_(n) ≧500, functionalization is bygroups of the formula --CO--Y--R³ wherein Y is O or S, and R³ is H,hydrocarbyl, substituted hydrocarbyl, aryl, or substituted aryl, andwherein, optionally, at least 50 mole % of the functional groups areattached to a tertiary carbon atom of the fractionated polymer backbone,the fractionated polymer prepared by fractionating a raw hydrocarbonpolymer to remove a light hydrocarbon fraction from said raw hydrocarbonpolymer prior to functionalization. The present invention is also afunctionalized hydrocarbon polymer wherein the polymer backbone hasM_(n) ≧500, the polymer backbone prior to functionalization containingless than about 1 weight percent hydrocarbon of carbon number C₂₄ andbelow, functionalization is by attachment of groups of the formula--CO--Y--R³ wherein Y is O or S, and R³ is H, hydrocarbyl, substitutedhydrocarbyl, aryl, or substituted aryl, and wherein, optionally, atleast 50 mole % of the functional groups are attached to a tertiarycarbon atom of the polymer backbone.

The present invention relates to an improved process forfunctionalization of fractionated hydrocarbon polymer wherein thefractionated polymer backbone has M_(n) ≧500 and light polymer (e.g.,less than 300 molecular weight) has been removed prior tofunctionalization and the functionalization is by groups of the formula:

    --CO--Y--R.sup.3

wherein Y is O or S, and either R³ is (i) H, hydrocarbyl and at least 50mole % of the functional groups are attached to a tertiary carbon atomof the polymer backbone or (ii) R³ is aryl, substituted aryl orsubstituted hydrocarbyl and, optionally, at least 50 mole % of thefunctional groups are attached to a tertiary carbon atom of the polymerbackbone.

Thus the functionalized fractionated polymer may be depicted by theformula:

    POLY--(CR.sup.1 R.sup.2 --CO--Y--R.sup.3).sub.n            (I)

wherein POLY is a fractionated hydrocarbon polymer backbone having anumber average molecular weight of at least 500, n is a number greaterthan 0, R¹, R² and R³ may be the same or different and are each H orhydrocarbyl with the optional provisos that either (1) R¹ and R² areselected such that at least 50 mole percent of the --CR¹ R² groupswherein both R¹ and R² are not H, or (2) when R³ is aryl, substitutedaryl or substituted hydrocarbyl, R¹ and R² are selected such that atleast 50 mole percent of the --CR¹ R² groups wherein both R¹ and R² arenot H.

In another aspect, the present invention relates to a lubricating oilnitrogen-containing dispersant additive exhibiting improved dispersancycomprising a nitrogen-containing polymeric material derived from afractionated polymer having a M_(n) of from about 700 to 10,000, a M_(w)/M_(n), (molecular weight distribution, MWD) of from about 1.2 to 3 andcontaining less than about 10 mole % of polymer chains having amolecular weight of less than 500. In one embodiment, thenitrogen-containing polymeric material comprises the reaction product ofan amine compound and functionalized, fractionated polymer prepared byfunctionalizing the fractionated polymer to contain mono- ordicarboxylic acid producing groups. The functionalization is preferablyvia the Koch reaction as herein described, but can be carried out by anyother methods suitable for introducing mono- or dicarboxylic acidproducing groups into the fractionated polymer, such as by reacting thefractionated polymer with a carboxylic reactant selected from the groupconsisting of a monounsaturated monocarboxylic acid producing compoundand a monounsaturated dicarboxylic acid producing compound.

In still another aspect, the present invention provides a process forpreparing a lubricating oil nitrogen-containing dispersant exhibitingimproved dispersancy properties which comprises: (A) functionalizing afractionated polymer having a M_(n) of from about 700 to 10,000 and aMWD of from about 1.2 to 3 and containing less than about 10 mole % ofpolymer chains having a molecular weight of less than 500; and (B)reacting said functionalized, fractionated polymer with anitrogen-containing compound. The functionalizing step preferablycomprises carbonylating the fractionated polymer using a Koch reaction,but can be by any suitable method for introducing mono- or dicarboxylicacid producing groups, such as by reacting the fractionated polymer witha carboxylic reactant selected from the group consisting of amonounsaturated monocarboxylic acid producing compound and amonounsaturated dicarboxylic acid producing compound. Thefunctionalization step can also be accomplished by alkylation of ahydroxy aromatic compound (e.g., phenol) with the fractionated polymer;the resulting polymer substituted hydroxy aromatic compound can then bederivatized by reaction with am aldehyde and a reactivenitrogen-containing compound (e.g., an alkylene polyamine) to form aMannich base dispersant.

As used herein the term "hydrocarbyl" denotes a group having a carbonatom directly attached to the remainder of the molecule and havingpredominantly hydrocarbon character within the context of this inventionand includes polymeric hydrocarbyl radicals. Such radicals include thefollowing:

(1) Hydrocarbon groups; that is, aliphatic, (e.g., alkyl or alkenyl),alicyclic (e.g., cycloalkyl or cycloalkenyl), aromatic, aliphatic- andalicyclic-substituted aromatic, aromatic-substituted aliphatic andalicyclic radicals, and the like, as well as cyclic radicals wherein thering is completed through another portion of the molecule (that is, thetwo indicated substituents may together form a cyclic radical). Suchradicals are known to those skilled in the art; examples include methyl,ethyl, butyl, hexyl, octyl, decyl, dodecyl, tetradecyl, octadecyl,eicosyl, cyclohexyl, phenyl and naphthyl (all isomers being included).Any hydrocarbyl radical containing aromatic is broadly referred toherein as "aryl".

(2) Substituted hydrocarbon groups; that is, radicals containingnon-hydrocarbon substituents which, in the context of this invention, donot alter predominantly hydrocarbon character of the radical. Thoseskilled in the art will be aware of suitable substituents (e.g., halo,hydroxy, alkoxy, carbalkoxy, nitro, alkylsulfoxy).

(3) Hetero groups; that is, radicals which, while predominantlyhydrocarbon in character within the context of this invention, containatoms other than carbon present in a chain or ring otherwise composed ofcarbon atoms. Suitable hetero atoms will be apparent to those skilled inthe art and include, for example, nitrogen particularly non-basicnitrogen which would deactivate the Koch catalyst, oxygen and sulfur.

In general, no more than about three substituents or hetero atoms, andpreferably no more than one, will be present for each 10 carbon atoms inthe hydrocarbon-based radical. Polymeric hydrocarbyl radicals are thosederived from hydrocarbon polymers, which may be substituted and/orcontain hetero atoms provided that they remain predominantly hydrocarbonin character.

Conversely, as used herein, the term "substituted hydrocarbyl" denotes aradical having a carbon atom directly attached to the remainder of themolecule, wherein the character of the radical is not exclusivelyhydrocarbon due to the presence of non-hydrocarbon substituents, such asthose noted above in describing "hydrocarbyl", or heteroatom groups inthe radical. Any substituted hydrocarbyl radical containing aromatic isbroadly referred to herein as "substituted aryl".

The functionalized fractionated polymer may be derived from ahydrocarbon polymer comprising non-aromatic carbon--carbon double bond,also referred to as an olefinically unsaturated bond, or an ethylenicdouble bond. The polymer is functionalized at that double bond via aKoch reaction to form the carboxylic acid, carboxylic ester or thio acidor thio ester. In one aspect, it is the object of this invention toremove light polymer or light hydrocarbon from the raw polymer prior tothe functionalization. In another aspect, it is the object of thisinvention to remove deeper cut polymer from the raw polymer prior to thefunctionalization.

While it is also possible to functionalize the raw polymer and to thenfractionate the functionalized raw polymer to remove functionalizedlight polymers or functionalized deeper cut polymers therefrom, this isnot preferred as additional manufacturing costs will generally result.

Koch reactions have not heretofore been applied to polymers havingnumber average molecular weights greater than 500. The hydrocarbonpolymer preferably has M_(n) greater than 1,000. In the Koch process apolymer having at least one ethylenic double bond is contacted with anacid catalyst and carbon monoxide in the presence of a nucleophilictrapping agent such as water or alcohol. The catalyst is preferably aclassical Broensted acid or Lewis acid catalyst. These catalysts aredistinguishable from the transition metal catalysts of the typedescribed in the prior art. The Koch reaction, as applied in the processof the present invention, may result in good yields of functionalizedpolymer, even 90 mole % or greater.

POLY, in general formula I, represents a fractionated hydrocarbonpolymer backbone having M_(n) of at least 500 with the polymer less than300 molecular weight removed, and/or light hydrocarbon of carbon numberC₄ to C₂₄. M_(n) may be determined by available techniques such as gelpermeation chromatography (GPC). POLY is derived from unsaturatedpolymer. Such GPC methods are useful in determining the molecular weightand molecular weight distribution of the raw polymer, the fractionatedpolymer, the light polymer and the deeper cut polymer.

Polymers

The polymers which are useful in the Koch reaction are polymerscontaining at least one carbon--carbon double bond (olefinic orethylenic) unsaturation. Thus, the maximum number of functional groupsper polymer chain is limited by the number of double bonds per chain.Such polymers have been found to be receptive to Koch mechanisms to formcarboxylic acids or derivatives thereof, using the catalysts andnucleophilic trapping agents of the present invention. It is known thatpolymers useful in the Koch process include polymers containing adistribution of molecular weights (MWD).

Useful polymers in the Koch reaction include polyalkenes includinghomopolymer, copolymer (used interchangeably with interpolymer) andmixtures. Homopolymers and interpolymers include those derived frompolymerizable olefin monomers of 2 to about 16 carbon atoms; usually 2to about 6 carbon atoms.

Particular reference is made to the alpha olefin polymers made usingorgano metallic coordination compounds. A particularly preferred classof polymers are ethylene alpha olefin copolymers such as those disclosedin U.S. Pat. No. 5,017,299. The polymer unsaturation can be terminal,internal or both. Preferred polymers have terminal unsaturation,preferably a high degree of terminal unsaturation. Terminal unsaturationis the unsaturation provided by the last monomer unit located in thepolymer. The unsaturation can be located anywhere in this terminalmonomer unit. Terminal olefinic groups include vinylidene unsaturation,R^(a) R^(b) C═CH² ; trisubstituted olefin unsaturation, R^(a) R^(b)C═CR^(c) H; vinyl unsaturation, R^(a) HC═CH₂ ; 1,2-disubstitutedterminal unsaturation, R^(a) HC═CHR^(b) ; and tetra-substituted terminalunsaturation, R^(a) R^(b) C═CR^(c) CR^(d). At least one of R^(a) andR^(b) is a polymeric group of the present invention, and the remainingR^(b), R^(c) and R^(d) are hydrocarbon groups as defined with respect toR, R¹, R², and R³ above.

Low molecular weight polymers, also referred to herein as dispersantrange molecular weight polymers, are polymers having M_(n) less than20,000, preferably 500 to 20,000 (e.g. 1,000 to 20,000), more preferably1,500 to 10,000 (e.g. 2,000 to 8,000) and most preferably from 1,500 to5,000. The number average molecular weights are measured by vapor phaseosmometry or GPC. Low molecular weight polymers are useful in formingdispersants for lubricant additives. In accordance with this invention,low molecular weight polymers are preferably removed by fractionation(e.g., stripping or distillation) to obtain fractionated polymers havingless than 10 mole % of deeper cut polymer chains, as described herein.

Medium molecular weight polymers M_(n) 's ranging from 20,000 to200,000, preferably 25,000 to 100,000; and more preferably, from 25,000to 80,000 are useful for viscosity index improvers for lubricating oilcompositions, adhesive coatings, tackifiers and sealants. The mediumM_(n) can be determined by membrane osmometry.

The higher molecular weight materials have M_(n) of greater than about200,000 and can range to 15,000,000 with specific embodiments of 300,000to 10,000,000 and more specifically 500,000 to 2,000,000. These polymersare useful in polymeric compositions and blends including elastomericcompositions. Higher molecular weight materials having M_(n) 's of from20,000 to 15,000,000 can be measured by gel permeation chromatographywith universal calibration, or by light scattering. The values of theratio M_(w) /M_(n), referred to as molecular weight distribution (MWD)are not critical. However, a typical minimum M_(w) /M_(n) value of about1.1-2.0 is preferred with typical ranges of about 1.1 up to about 4.

More preferably, the polymer material used for preparing thenitrogen-containing dispersant additives of this invention havingimproved dispersancy properties comprises a fractionated polymer havinga M_(n) of from about 700 to 10,000, more preferably from about 800 to5,000, and most preferably from about 1,000 to 4,000 and a MWD of fromabout 1.2 to 3, most preferably from about 1.2 to 2.5, and containingless than about 10 mole % (preferably less than about 5 mole %, morepreferably less than about 3 mole %) of polymer chains having amolecular weight of less than 500. Lubricating oil dispersant additivesprepared from such fractionated polymers have been found to exhibitsurprisingly improved dispersancy properties in internal combustionengine, crankcase lubricating oil applications.

The olefin monomers are preferably polymerizable terminal olefins; thatis, olefins characterized by the presence in their structure of thegroup --R--C═CH₂, where R is H or a hydrocarbon group. However,polymerizable internal olefin monomers (sometimes referred to in thepatent literature as medial olefins) characterized by the presencewithin their structure of the group: ##STR2## can also be used to formthe polyalkenes. When internal olefin monomers are employed, theynormally will be employed with terminal olefins to produce polyalkeneswhich are interpolymers. For this invention, a particular polymerizedolefin monomer which can be classified as both a terminal olefin and aninternal olefin, will be deemed a terminal olefin. Thus, pentadiene-1,3(i.e., piperylene) is deemed to be a terminal olefin.

While the polyalkenes generally are hydrocarbon polyalkenes, they cancontain substituted hydrocarbon groups such as lower alkoxy, lower alkylmercapto, hydroxy, mercapto, and carbonyl, provided the non-hydrocarbonmoieties do not substantially interfere with the functionalization orderivatization reactions of this invention. When present, suchsubstituted hydrocarbon groups normally will not contribute more thanabout 10% by weight of the total weight of the polyalkenes. Since thepolyalkene can contain such non-hydrocarbon substituent, it is apparentthat the olefin monomers from which the polyalkenes are made can alsocontain such substituents. As used herein, the term "lower" when usedwith a chemical group such as in "lower alkyl" or "lower alkoxy" isintended to describe groups having up to seven carbon atoms.

The polyalkenes may include aromatic groups and cycloaliphatic groupssuch as would be obtained from polymerizable cyclic olefins orcycloaliphatic substituted-polymerizable acrylic olefins. There is ageneral preference for polyalkenes free from aromatic and cycloaliphaticgroups (other than the diene styrene interpolymer exception alreadynoted). There is a further preference for polyalkenes derived fromhomopolymers and interpolymers of terminal hydrocarbon olefins of 2 to16 carbon atoms. This further preference is qualified by the provisothat, while interpolymers of terminal olefins are usually preferred,interpolymers optionally containing up to about 40% of polymer unitsderived from internal olefins of up to about 16 carbon atoms are alsowithin a preferred group. A more preferred class of polyalkenes arethose selected from the group consisting of homopolymers andinterpolymers of terminal olefins of 2 to 6 carbon atoms, morepreferably 2 to 4 carbon atoms. However, another preferred class ofpolyalkenes are the latter, more preferred polyalkenes optionallycontaining up to about 25% of polymer units derived from internalolefins of up to about 6 carbon atoms.

Specific examples of terminal and internal olefin monomers which can beused to prepare the polyalkenes according to conventional, well-knownpolymerization techniques include ethylene; propylene; butene-1;butene-2; isobutene; pentene-1; etc.; propylene-tetramer; diisobutylene;isobutylene trimer; butadiene-1,2; butadiene-1,3; pentadiene-1,2;pentadiene-1,3; etc.

Useful polymers include alpha-olefin homopolymers and interpolymers, andethylene alpha-olefin copolymers and terpolymers. Specific examples ofpolyalkenes include polypropylenes, polybutenes, ethylene-propylenecopolymers, ethylene-butene copolymers, propylene-butene copolymers,styrene-isobutene copolymers, isobutene-butadiene-1,3 copolymers, etc.,and terpolymers of isobutene, styrene and piperylene and copolymer of80% of ethylene and 20% of propylene. A useful source of polyalkenes arethe poly(isobutene)s obtained by polymerization of C₄ refinery streamhaving a butene content of about 35 to about 75% by wt., and anisobutene content of about 30 to about 60% by wt., in the presence of aLewis acid catalyst such as aluminum trichloride or boron trifluoride.

Also useful are the high molecular weight poly-n-butenes of U.S. Ser.No. 992,871 filed Dec. 17, 1992.

A preferred source of monomer for making poly-n-butenes is petroleumfeedstreams such as Raffinate II. These feedstocks are disclosed in theart such as in U.S. Pat. No. 4,952,739.

Ethylene Alpha-Olefin Copolymer

Preferred polymers are polymers of ethylene and at least onealpha-olefin having the formula H₂ C═CHR⁴ wherein R⁴ is straight chainor branched chain alkyl radical comprising 1 to 18 carbon atoms andwherein the polymer contains a high degree of terminal ethenylideneunsaturation. Preferably R⁴ in the above formula is alkyl of from 1 to 8carbon atoms and more preferably is alkyl of from 1 to 2 carbon atoms.Therefore, useful comonomers with ethylene in this invention includepropylene, 1-butene, hexene-1, octene-1, etc., and mixtures thereof(e.g. mixtures of propylene and 1-butene, and the like). Preferredpolymers are copolymers of ethylene and propylene and ethylene andbutene-1.

The molar ethylene content of the polymers employed is preferably in therange of between about 20 and about 80%, and more preferably betweenabout 30 and about 70%. When butene-1 is employed as comonomer withethylene, the ethylene content of such copolymer is most preferablybetween about 20 and about 45 wt %, although higher or lower ethylenecontents may be present. The most preferred ethylene-butene-1 copolymersare disclosed in U.S. Ser. No. 992,192, filed Dec. 17, 1992. Thepreferred method for making low molecular weight ethylene/α-olefincopolymer is described in U.S. Ser. No. 992,690, filed Dec. 17, 1992.

Preferred ranges of number average molecular weights of polymer for useas precursors for dispersants are from 500 to 10,000, preferably from1,000 to 8,000, most preferably from 2,500 to 6,000. A convenient methodfor such determination is by size exclusion chromatography (also knownas gel permeation chromatography (GPC)) which additionally providesmolecular weight distribution information. Such polymers generallypossess an intrinsic viscosity (as measured in tetralin at 135° C.) ofbetween 0.025 and 0.6 dl/g, preferably between 0.05 and 0.5 dl/g, mostpreferably between 0.075 and 0.4 dl/g. These polymers preferably exhibita degree of crystallinity such that, when grafted, they are essentiallyamorphous.

The preferred ethylene alpha-olefin polymers are further characterizedin that up to about 95% and more of the polymer chains possess terminalvinylidene-type unsaturation. Thus, one end of such polymers will be ofthe formula POLY-C(R¹¹)=CH₂ wherein R¹¹ is C₁ to C₁₈ alkyl, preferablyC₁ to C₈ alkyl, and more preferably methyl or ethyl and wherein POLYrepresents the polymer chain. A minor amount of the polymer chains cancontain terminal ethenyl unsaturation, i.e. POLY--CH═CH₂, and a portionof the polymers can contain internal monounsaturation, e.g.POLY--CH═CH(R¹¹), wherein R¹¹ is as defined above.

The preferred ethylene alpha-olefin polymer comprises polymer chains, atleast about 30% of which possess terminal vinylidene unsaturation.Preferably at least about 50%, more preferably at least about 60%, andmost preferably at least about 75% (e.g. 75 to 98%), of such polymerchains exhibit terminal vinylidene unsaturation. The percentage ofpolymer chains exhibiting terminal vinylidene unsaturation may bedetermined by FTIR spectroscopic analysis, titration, HNMR or carbon-13NMR.

Another preferred class of polymers are alpha-olefin polymers; i.e.,alpha-olefin homopolymers of an alpha-olefin of formula H₂ C═CHR⁴ andalpha-olefin interpolymers of two or more alpha-olefins of formula H₂C═CHR⁴, wherein R⁴ is as defined above. The preferred alpha-olefinmonomers are butene-1 and propylene and preferred alpha-olefin polymersare polypropylene, polybutene-1 and butene-1propylene copolymer (e.g.,butene-1-propylene copolymers having 5 to 95 mole %, more typically 5 to40 mole %, propylene). Preferred alpha-olefin polymers comprise polymerchains possessing high terminal unsaturation; i.e., at least about 30%,preferably at least about 50%, more preferably at least about 60%, andmost preferably at least about 75% (e.g., 75 to 98%) of the chains haveterminal vinylidene unsaturation. Isotactic and atactic polypropylenesare also useful examples of alpha-olefin polymers.

The polymers can be prepared by polymerizing monomer mixtures comprisingethylene with other monomers such as alpha-olefins, preferably from 3 to4 carbon atoms in the presence of a metallocene catalyst systemcomprising at least one metallocene (e.g., a cyclopentadienyl-transitionmetal compound) and an activator, e.g. alumoxane compound. The comonomercontent can be controlled through selection of the metallocene catalystcomponent and by controlling partial pressure of the monomers.

The catalyst is preferably a bulky ligand transition metal compound. Thebulky ligand may contain a multiplicity of bonded atoms, preferablycarbon atoms, forming a group which may be cyclic with one or moreoptional heteroatoms. The bulky ligand may be a cyclopentadienylderivative which can be mono- or polynuclear. One or more bulky ligandsmay be bonded to the transition metal atom. The transition metal atommay be a Group IV, V or VI transition metal ("Group" refers to anidentified group of the Periodic Table of Elements, comprehensivelypresented in "Advanced Inorganic Chemistry," F. A. Cotton, G. Wilkinson,Fifth Edition, 1988, John Wiley & Sons). Other ligands may be bonded tothe transition metal, preferably detachable by a cocatalyst such as ahydrocarbyl or halogen leaving group. The catalyst is derivable from acompound of the formula

     L!.sub.m M X!.sub.n

wherein L is the bulky ligand, X is the leaving group, M is thetransition metal and m and n are such that the total ligand valencycorresponds to the transition metal valency. Preferably the catalyst isfour coordinate such that the compound is ionizable to a 1⁺ valencystate.

The ligands L and X may be bridged to each other and if two ligands Land/or X are present, they may be bridged. The metallocenes may befull-sandwich compounds having two ligands L which are cyclopentadienylgroups or half-sandwich compounds having one ligand L only which is acyclopentadienyl group.

For the purposes of this patent specification the term "metallocene" isdefined to contain one or more cyclopentadienyl moiety in combinationwith a transition metal of the Periodic Table of Elements. In oneembodiment the metallocene catalyst component is represented by thegeneral formula (Cp)_(m) MR_(n) R'_(p) wherein Cp is a substituted orunsubstituted cyclopentadienyl ring; M is a Group IV, V or VI transitionmetal; R and R' are independently selected halogen, hydrocarbyl group,or hydrocarboxyl groups having 1-20 carbon atoms; m=1-3, n=0-3, p=0-3,and the sum of m+n+p equals the oxidation state of M. In anotherembodiment the metallocene catalyst is represented by the formulas:

    (C.sub.5 R'.sub.m).sub.p R".sub.s (C.sub.5 R'.sub.m)MeQ.sub.3-p-x and

    R".sub.s (C.sub.5 R'.sub.m).sub.2 MeQ'

wherein Me is a Group IV, V, or VI transition metal C₅ R'_(m) is asubstituted cyclopentadienyl each R', which can be the same or differentis hydrogen, alkenyl aryl alkaryl or arylalkyl radical having from 1 to20 carbon atoms or two carbon atoms joined together to form a part of aC₄ to C₆ ring, R" is one or more of or a combination of a carbon, agermanium, a silicon, a phosphorous or a nitrogen atom containingradical substituting on a bridging two C₅ R'_(m) rings or bridging oneC₅ R'_(m) ring back to Me, when p=0 and x=1 otherwise x is always equalto 0, each Q which can be the same or different is an aryl alkyl,alkenyl, alkaryl, or arylalkyl radical having from 1 to 20 carbon atomsor halogen, Q' is an alkylidene radical having from 1 to 20 carbonatoms, s is 0 or 1 and when s is 0, m is 5 and p is 0, 1 or 2 and when sis 1, m is 4 and p is 1.

Various forms of the catalyst system of the metallocene type may be usedin the polymerization process of this invention. Exemplary of thedevelopment of metallocene catalysts in the art for the polymerizationof ethylene is the disclosure of U.S. Pat. No. 4,871,705 to Hoel, U.S.Pat. No. 4,937,299 to Ewen, et al. and EP-A-0129368 published Jul. 26,1989, and U.S. Pat. No. 5,017,714 and U.S. Pat. No. 5,120,867 toWelborn, Jr. These publications teach the structure of the metallocenecatalysts and include alumoxane as the cocatalyst. There are a varietyof methods for preparing alumoxane, one of which is described in U.S.Pat. No. 4,665,208.

For the purposes of this patent specification, the terms "cocatalysts oractivators" are used interchangeably and are defined to be any compoundor component which can activate a bulky ligand transition metalcompound. In one embodiment the activators generally contain a metal ofGroup II and III of the Periodic Table of Elements. In the preferredembodiment, the bulky transition metal compound are metallocenes, whichare activated by trialkylaluminum compounds, alumoxanes both linear andcyclic, or ionizing ionic activators or compounds such as tri (n-butyl)ammonium tetra (pentafluorophenyl) boron, which ionize the neutralmetallocene compound. Such ionizing compounds may contain an activeproton, or some other cation associated with but not coordinated, oronly loosely coordinated to the remaining ion of the ionizing ioniccompound. Such compounds are described in EP-A-0520 732, EP-A-0 277 003and EP-A-0 277 004 published Aug. 3, 1988, and U.S. Pat. Nos. 5,153,157;5,198,401 and 5,241,025. Further, the metallocene catalyst component canbe a monocyclopentadienyl heteroatom containing compound. Thisheteroatom is activated by either an alumoxane or an ionic activator toform an active polymerization catalyst system to produce polymers usefulin this invention. These types of catalyst systems are described in, forexample, PCT International Publication WO 92/00333 published Jan. 9,1992, U.S. Pat. Nos. 5,057,475; 5,096,867; 5,055,438 and 5,227,440 andEP-A-0 420 436, WO 91/04257. In addition, the metallocene catalystsuseful in this invention can include non-cyclopentadienyl catalystcomponents, or ancillary ligands such as boroles or carbollides incombination with a transition metal. Additionally, it is not beyond thescope of this invention that the catalysts and catalyst systems may bethose described in U.S. Pat. No. 5,064,802 and PCT publications WO93/08221 and WO 93/08199 published Apr. 29, 1993. All the catalystsystems of the invention may be, optionally, prepolymerized or used inconjunction with an additive or scavenging component to enhancecatalytic productivity.

The polymer for use in the Koch reaction can include block and taperedcopolymers derived from monomers comprising at least one conjugateddiene with at least monovinyl aromatic monomer, preferably styrene. Suchpolymers should not be completely hydrogenated so that the polymericcomposition contains olefinic double bonds, preferably at least one bondper molecule. The Koch reaction can also include star polymers asdisclosed in patents such as U.S. Pat. Nos. 5,070,131; 4,108,945;3,711,406; and 5,049,294.

Polymer Fractionation

Polymers useful for dispersants in lubricant applications can comprise amixture or distribution of molecular weights. This distribution is aresult of the processes used to make the polymers. Number averagemolecular weight is a useful way to represent the molecular weightdistribution.

It has been found desirable to minimize or reduce, or eliminatecompletely, the amount of lower molecular weight polymers (e.g., lightpolymers) or monomers such as unreacted higher olefins from a givenpolymer molecular weight distribution to improve the performance of thefinal product.

In the Koch process as described herein, it has been found useful tominimize the amount of low molecular weight functionalized product(i.e., light functionalized product such as light ester) formed duringthe carbonylation step. Light functionalized product can be formed bytwo routes. Route one involves the introduction of light functionalizedproduct precursors such as C₄ to C₂₄ olefins which are impurities in thepolymer feed. Route two may involve the generation of breakdown productsduring the carbonylation reaction.

This invention relates to "route one". It has been found that byfractionating the raw polymer feed to remove light polymer and unreactedmonomers such as olefins prior to the carbonylation step the amount ofundesirable light functionalized polymer (e.g., polymer esters) that isgenerated is reduced and it has been further found that the polymer thusfunctionalized can be reacted with a nitrogen-containing compound toprepare a derivative of the fractionated polymer that has improvedlubricating oil dispersant properties. The fractionating of the polymerfeed can be accomplished by any suitable means, such as by distillationwith or without a (partial) vacuum, by stripping with an inert gas(e.g., nitrogen) with or without a (partial) vacuum, by solventextraction, or by selective sorption or the like. The fractionation cantake place in a batch or continuous process. The process equipmentutilized is not critical providing that the necessary conditions oftemperature and negative pressure (e.g., vacuum) can be met. A shortpath evaporator (or wiped film evaporator) is a useful means fordistilling the polymers and is known in the art. A typical short pathevaporator comprises a vessel with product feed, and residue dischargemeans, a heating means and a distillate overhead with a condenser, acollector and vacuum pump. The evaporator should be equipped with acondenser and collector means for recovery and disposal of the lightpolymer removed from the polymer feed.

The evaporator should have sufficient volume to handle useful quantitiesof polymer feed (e.g., 50 kilograms per hour for a pilot unit and morefor a commercial facility). The evaporator should be capable of heatingthe polymer feed to temperature high enough for efficient evaporation ofthe light polymer. Suitable temperatures are in the range of 180° to300° C., preferably 200° to 240° C., most preferably 220° to 230° C. Theevaporator may operate at atmospheric pressure but it is preferable tooperate under negative pressure (e.g., vacuum) for more efficientdistilling. Suitable vacuum is in the range of 0.5 to 50 mm Hg,preferably 1.0 to 30 mm Hg, more preferably 1.5 to 20 mm Hg. Theefficiency of the light polymer removal may be improved by optionalagitation of the polymer feed in the evaporator or by the use of inertgas stripping (e.g., nitrogen stripping) to assist in separating thelight polymer from the polymer residue. Techniques such as these areknown in the art.

Carbonylation is the part of the functionalization process wherein theunsaturated polymer is reacted with carbon monoxide in the presence ofan acid catalyst, preferably BF₃, and a nucleophilic trapping agent,conveniently a halophenol such as 2,4-dichlorophenol, or, preferably2-chloro-4-methylphenol. The resultant product is an ester with anattendant leaving group. This functionalized product can be subsequentlyderivatized with an amine to form the useful dispersant for lubricantadditive applications. An excess over the stoichiometric amount of thehalophenol is used in the reaction and it is necessary to remove theunreacted halophenol from the crude ester produced in the reaction andrecover it for reuse. The crude ester produced in the carbonylationreaction consists essentially of unreacted halophenol, impurities andthe functionalized polymer. The functionalized polymer includes lowermolecular weight polymer and unreacted olefin monomers which range incarbon number from C₄ to C₂₄, which have been esterified.

The unreacted halophenol can be removed from the crude polymer ester ina process of evaporation, stripping, or distillation. Processes of thistype are known in the art and can be run in equipment such as flashdrums, falling film evaporators, forced film or wiped film evaporators,or short path evaporators or the like. In general, this equipmentcomprises a vessel or pipe wherein a liquid mass is heated to atemperature at which volatile material evaporates from the liquid mass.The process can be run at atmospheric pressure or under negativepressure (e.g., vacuum). Negative pressure is preferable. Agitation canbe beneficial to assist in liquid/vapor disengagement. Use of an inertgas (e.g., nitrogen) passing through the liquid mass can also assist inliquid/vapor disengagement.

For removal of volatiles from viscous liquids, forced film or short pathevaporators are preferred. Short path evaporators are particularlyuseful. Once the unreacted halophenol is removed from the crude polymerester it is desired to condense and collect it for subsequent reuse.This can be achieved by use of a condenser and collector either externalor internal to the short path evaporator. During the evaporation,components that boil lower than the functionalized polymer, such as thehalophenol, light esters and chlorinated mixtures are removed overheadto the distillate stream. The bottom product of functionalized polymeris subsequently derivatized in an amination reactor.

The distillate is collected and then fractionally distilled to recoverand recycle the unreacted halophenol. However, some of the impurities,especially light esters that boil close to halophenol as well as lighthalogenated compounds, are also inadvertently recycled. Ultimately therecycle stream will become saturated with undesirable components. Sincethe evaporation is a single stage operation, an equilibrium level ofundesirables will build up in the process streams. The levels of lightester will increase in the residue product, possibly adversely affectingthe performance of the final dispersant. In order to maintain lowimpurity levels, the distillate might have to be frequently purged. Thisis very costly. Thus, it is very desirable to minimize the amount oflight ester present in the crude ester fed to the evaporators.

Hence, removal of the light ester precursors (C₄ to C₂₄ olefinicmonomers or polymers) from the polymer prior to the carbonylation stepis desirable.

Koch Reaction

In the Formula I, the letter n is generally greater than 0 andrepresents the functionality (F) or average number of functional groupsper polymer chain, based on the polymer introduced into the Kochreaction. Thus, functionality can be expressed as the average number ofmoles of functional groups per "mole of polymer" charged to thefunctionalization reactor. Accordingly, F corresponds to n of Formula(I). The functionalized polymer product will generally include polymermolecules having no functional groups. Specific preferred embodiments ofn include 1≧n>0; 2≧n>1; and n>2. n can be determined by carbon-13 NMR.The optimum number of functional groups needed for desired performancewill typically increase with M_(n) of the polymer. The maximum value ofn will be determined by the number of double bonds per polymer chain inthe unfunctionalized polymer.

In specific and preferred embodiments the "leaving group" (--YR³) has apKa of less than or equal to 12, preferably less than 10, and morepreferably less than 8. The pKa is determined from the correspondingacidic species HY--R³ in water at room temperature.

Where the leaving group is a simple acid or alkyl ester, thefunctionalized polymer is very stable especially as the % neosubstitution increases. The Koch reaction is especially useful to make"neo" functionalized polymers which are generally more stable and lesslabile than iso structures. In preferred embodiments the polymer can beat least 60, more preferably at least 80 mole percent neofunctionalized.The polymer can be greater than 90, or 99 and even about 100 molepercent neo.

In one preferred composition the polymer defined by formula (I), Y is O(oxygen), and R¹ and R² are be the same or different and are selectedfrom H, a hydrocarbyl group, and a polymeric group.

In another preferred embodiment Y is O or S, R¹ and R² are the same ordifferent and are selected from H, a hydrocarbyl group a substitutedhydrocarbyl group and a polymeric group, and R³ is selected from asubstituted hydrocarbyl group, an aromatic group (aryl) and asubstituted aromatic group (substituted aryl). This embodiment isgenerally more reactive towards derivatization with amines and alcoholcompounds especially where the R³ substituent contains electronwithdrawing species. It has been found that in this embodiment, apreferred leaving group, HYR³, has a pKa of less than 12, preferablyless than 10 and more preferably 8 or less. pKa values can rangetypically from 5 to 12, preferably from 6 to 10, and most preferablyfrom 6 to 8. The pKa of the leaving group determines how readily thesystem will react with derivatizing compounds to produce derivatizedproduct.

In a particularly preferred composition, R³ is represented by theformula: ##STR3## wherein X each of which may be the same or different,is an electron withdrawing substituent, T, each of which may be the sameor different, represents a non-electron withdrawing substituent (e.g.electron donating), and m and p are from 0 to 5 with the sum of m and pbeing from 0 to 5. More preferably, m is from 1 to 5 and preferably 1 to3. In a particularly preferred embodiment X is selected from a halogen,preferably F or Cl, CF₃, cyano groups and nitro groups and p=0. Apreferred R³ is derived from 2,4-dichlorophenol.

The composition derived from the present invention includes derivatizedpolymer which is the reaction product of the Koch functionalized polymerand a derivatizing compound. Preferred derivatizing compounds includenucleophilic reactant compounds including amines, alcohols,amino-alcohols, metal reactant compounds and mixtures thereof.Derivatized polymer will typically contain at least one of the followinggroups: amide, imide, oxazoline, and ester, and metal salt. Thesuitability for a particular end use may be improved by appropriateselection of the polymer. M_(n) and functionality used in thederivatized polymer is discussed hereinafter.

The Koch reaction permits controlled functionalization of unsaturatedpolymers. When a carbon of the carbon--carbon double bond is substitutedwith hydrogen, it will result in an "iso" functional group, i.e. one ofR¹ or R² of Formula I is H; or when a carbon of the double bond is fullysubstituted with hydrocarbyl groups it will result in an "neo"functional group, i.e. both R¹ or R² of Formula I are non-hydrogengroups.

Polymers produced by processes which result in a terminally unsaturatedpolymer chain can be functionalized to a relatively high yield inaccordance with the process of the present invention. It has been foundthat the neo acid functionalized polymer can be derivatized to arelatively high yield. The Koch process also makes use of relativelyinexpensive materials i.e., carbon monoxide at relatively lowtemperatures and pressures. Also the leaving group --YR³ can be removedand recycled upon derivatizing the Koch functionalized polymer withamines or alcohols. The functionalized or derivatized polymers of thepresent invention are useful as lubricant additives such as dispersants,viscosity improvers and multifunctional viscosity improvers. Thecomposition derived from the present invention includes oleaginouscompositions comprising the above functionalized, and/or derivatizedpolymer. Such compositions include lubricating oil compositions andconcentrates. The Koch reaction also provides a process which comprisesthe step of catalytically reacting in admixture: (a) at least onefractionated hydrocarbon polymer as described herein and containingethylenic double bonds; (b) carbon monoxide, (c) at least one acidcatalyst, and (d) a nucleophilic trapping agent selected from the groupconsisting of water, hydroxy-containing compounds and thiol-containingcompounds, the reaction being conducted a) in the absence of reliance ontransition metal as a catalyst; or b) with at least one acid catalysthaving a Hammett acidity of less than -7; or c) wherein functionalgroups are formed at least 40 mole % of the ethylenic double bonds; ord) wherein the nucleophilic trapping agent has a pKa of less than 12.

The process of the present invention relates to a polymer having atleast one ethylenic double bond reacted via a Koch mechanism to formcarbonyl or thio carbonyl group-containing compounds, which maysubsequently be derivatized. The polymers react with carbon monoxide inthe presence of an acid catalyst or a catalyst preferably complexed withthe nucleophilic trapping agent. A preferred catalyst is BF₃ andpreferred catalyst complexes include BF₃.H₂ O and BF₃ complexed with2,4-dichlorophenol. The starting polymer reacts with carbon monoxide atpoints of unsaturation to form either iso- or neo-acyl groups with thenucleophilic trapping agent, e.g. with water, alcohol (preferably asubstituted phenol) or thiol to form respectively a carboxylic acid,carboxylic ester group, or thio ester.

In a preferred process, at least one polymer having at least onecarbon--carbon double bond is contacted with an acid catalyst orcatalyst complex having a Hammett Scale acidity value of less than -7,preferably from -8.0 to -11.5 and most preferably from -10 to -11.5.Without wishing to be bound by any particular theory, it is believedthat a carbenium ion may form at the site of one of carbon--carbondouble bonds. The carbenium ion may then react with carbon monoxide toform an acylium cation. The acylium cation may react with at least onenucleophilic trapping agent as defined herein.

At least 40 mole %, preferably at least 50 mole %, more preferably atleast 80 mole %, and most preferably 90 mole % of the polymer doublebonds will react to form acyl groups wherein the non-carboxyl portion ofthe acyl group is determined by the identity of the nucleophilictrapping agent, i.e. water forms acid, alcohol forms acid ester andthiol forms thio ester. The polymer functionalized by the recitedprocess of the present invention can be isolated using fluoride salts.The fluoride salt can be selected from the group consisting of ammoniumfluoride, and sodium fluoride.

Preferred nucleophilic trapping agents are selected from the groupconsisting of water, monohydric alcohols, polyhydric alcoholshydroxyl-containing aromatic compounds and hetero substituted phenoliccompounds. The catalyst and nucleophilic trapping agent can be addedseparately or combined to form a catalytic complex.

Following is an example of a terminally unsaturated polymer reacted viathe Koch mechanism to form an acid or an ester. The polymer is contactedwith carbon monoxide or a suitable carbon monoxide source such as formicacid in the presence of an acidic catalyst. The catalyst contributes aproton to the carbon--carbon double bond to form a carbenium ion. Thisis followed by addition of CO to form an acylium ion which reacts withthe nucleophilic trapping agent. POLY, Y, R¹, R² and R³ are defined asabove. ##STR4##

The Koch reaction is particularly useful to functionalize poly(alphaolefins) and ethylene alpha olefin copolymers formed usingmetallocene-type catalysts. These polymers contain terminal vinylidenegroups. There is a tendency for such terminal groups to predominate andresult in neo-type (tertiary) carbenium ions. In order for the carbeniumion to form, the acid catalyst is preferably relatively strong. However,the strength of the acid catalyst is preferably balanced againstdetrimental side reactions which can occur when the acid is too strong.

The Koch catalyst can be employed by preforming a catalyst complex withthe proposed nucleophilic trapping agent or by adding the catalyst andtrapping agent separately to the reaction mixture. This later embodimenthas been found to be a particular advantage since it eliminates the stepof making the catalyst complex.

The following are examples of acidic catalyst and catalyst complexmaterials with their respective Hammett Scale Value acidity: 60% H₂ SO₄,-4.32; BF₃.3H₂ O, -4.5; BF₃.2H₂ O, -7.0; WO₃ /Al₂ O₃, less than -8.2;SiO₂ /Al₂ O₃, less than -8.2; HF, -10.2; BF₃.H₂ O, -11.4; -11.94; ZrO₂less than -12.7; SiO₂ /Al₂ O₃, -12.7 to -13.6; AlCl₃, -13.16 to -13.75;AlCl₃ /CuSO₄, -13.75 to -14.52.

It has been found that BF₃.2H₂ O is ineffective at functionalizingpolymer through a Koch mechanism ion with polymers. In contrast, BF₃.H₂O resulted in high yields of carboxylic acid for the same reaction. Theuse of H₂ SO₄ as a catalyst involves control of the acid concentrationto achieve the desired Hammett Scale Value range. Preferred catalystsare H₂ SO₄ and BF₃ catalyst systems.

Suitable BF₃ catalyst complexes for use in the present invention can berepresented by the formula:

    BF.sub.3.xHOR

wherein R can represent hydrogen, hydrocarbyl (as defined below inconnection with R') --CO--R', --SO₂ --R', --PO--(OH)₂, and mixturesthereof wherein R' is hydrocarbyl, typically alkyl, e.g., C₁ to C₂₀alkyl, and, e.g., C₆ to C₁₄ aryl, aralkyl, and alkaryl, and x is lessthan 2.

Following reaction with CO, the reaction mixture is further reacted withwater or another nucleophilic trapping agent such as an alcohol orphenolic, or thiol compound. The use of water releases the catalyst toform an acid. The use of hydroxy trapping agents releases the catalystto form an ester, the use of a thiol releases the catalyst to form athio ester.

Koch product, also referred to herein as functionalized polymer,typically will be derivatized as described hereinafter. Derivatizationreactions involving ester functionalized polymer will typically have todisplace the alcohol derived moiety therefrom. Consequently, the alcoholderived portion of the Koch functionalized polymer is sometimes referredto herein as a leaving group. The ease with which a leaving group isdisplaced during derivatization will depend on its acidity, i.e. thehigher the acidity the more easily it will be displaced. The acidity inturn of the alcohol is expressed in terms of its pKa.

Preferred nucleophilic trapping agents include water and hydroxy groupcontaining compounds. Useful hydroxy trapping agents include aliphaticcompounds such as monohydric and polyhydric alcohols or aromaticcompounds such as phenols and naphthols. The aromatic hydroxy compoundsfrom which the esters of this invention may be derived are illustratedby the following specific examples: phenol, naphthol, cresol,resorcinol, catechol, the chlorophenols.

The alcohols preferably can contain up to about 40 aliphatic carbonatoms. They may be monohydric alcohols such as methanols, ethanol,benzyl alcohol, 2-methylcyclohexanol, beta-chloroethanol, monomethylether of ethylene glycol, etc. The polyhydric alcohols preferablycontain from 2 to about 5 hydroxy radicals; e.g., ethylene glycol,diethylene glycol. Other useful polyhydric alcohols include glycerol,monomethyl ether of glycerol, and pentaerythritol. Useful unsaturatedalcohols include allyl alcohol, and propargyl alcohol. Particularlypreferred alcohols include those having the formula R*₂ CHOH where an R*is independently hydrogen, an alkyl, aryl, hydroxyalkyl, or cycloalkyl.Specific alcohols include alkanols such as methanol, ethanol, etc. Alsopreferred useful alcohols include aromatic alcohols, phenolic compoundsand polyhydric alcohols as well as monohydric alcohols such as1,4-butanediol.

It has been found that neo-acid ester functionalized polymer isextremely stable due, it is believed, to stearic hindrance.Consequently, the yield of derivatized polymer obtainable therefrom willvary depending on the ease with which a derivatizing compound candisplace the leaving group of the functionalized polymer.

The most preferred alcohol trapping agents may be obtained bysubstituting a phenol with at least one electron withdrawing substituentsuch that the substituted phenol possesses a pKa within the abovedescribed preferred pKa ranges. In addition, phenol may also besubstituted with at least one non-electron withdrawing substituent(e.g., electron donating), preferably at positions meta to the electronwithdrawing substituent to block undesired alkylation of the phenol bythe polymer during the Koch reaction. This further improves yield todesired ester functionalized polymer.

Accordingly, and in view of the above, the most preferred trappingagents are phenolic and substituted phenolic compounds represented bythe formula: ##STR5## wherein X, which may be the same or different, isan electron withdrawing substituent, and T which may be the same ordifferent is a non-electron withdrawing group; m and p are from 0 to 5with the sum of m and p being from 0 to 5, and m is preferably from 1 to5, and more preferably, m is 1 or 2. X is preferably a group selectedfrom halogen, cyano, and nitro, preferably located at the 2- and/or 4-position, and T is a group selected from hydrocarbyl, and hydroxy groupsand p is 1 or 2 with T preferably being located at the 4 and/or 6position. More preferably X is selected from Cl, F, Br, cyano or nitrogroups and m is preferably from 1 to 5, more preferably from 1 to 3, andmore preferably 1 to 2.

A particularly preferred group of trapping agents encompassed by Formula(V) are the halophenols and especially the chlorophenols includingmonochlorophenols such as 2-chlorophenol and 4-chlorophenol,dichlorophenols such as 2,4-dichlorophenol, and chloroalkylphenols suchas 2-chloro4-methylphenol and 4-chloro-2-methylphenol. The trappingagent is preferably selected from 2,4-dichlorophenol and2-chloro4-methyl phenol, and is most preferably 2-chloro4-methylphenol.

The relative amounts of reactants and catalyst, and the conditionscontrolled in a manner sufficient to functionalize typically at leastabout 40, preferably at least about 80, more preferably at least about90 and most preferably at least about 95 mole % of the carbon--carbondouble bonds initially present in the unfunctionalized polymer.

The amount of H₂ O, alcohol, or thiol used is preferably at least thestoichiometric amount required to react with the acylium cations. It ispreferred to use an excess of alcohol over the stoichiometric amount.The alcohol performs the dual role of reactant and diluent for thereaction. However, the amount of the alcohol or water used should besufficient to provide the desired yield yet at the same time not dilutethe acid catalyst so as to adversely affect the Hammett Scale Valueacidity.

The polymer added to the reactant system can be in a liquid phase.Optionally, the polymer can be dissolved in an inert solvent. The yieldcan be determined upon completion of the reaction by separating polymermolecules which contain acyl groups which are polar and hence can easilybe separated from unreacted non-polar compounds. Separation can beperformed using absorption techniques which are known in the art. Theamount of initial carbon--carbon double bonds and carbon--carbon doublebonds remaining after the reaction can be determined by C¹³ NMRtechniques.

In accordance with the process, the polymer is heated to a desiredtemperature range which is typically between -20° C. to 200° C.,preferably from 0° C. to 80° C. and more preferably from 20° C. to 65°C. Temperature can be controlled by heating and cooling means applied tothe reactor. Since the reaction is exothermic usually cooling means arerequired. Mixing is conducted throughout the reaction to assure auniform reaction medium.

The catalyst (and nucleophilic trapping agent) can be prereacted to forma catalyst complex or are charged separately in one step to the reactorto form the catalyst complex in situ at a desired temperature andpressure, preferably under nitrogen. In a preferred system thenucleophilic trapping agent is a substituted phenol used in combinationwith BF₃. The reactor contents are continuously mixed and then rapidlybrought to a desired operating pressure using a high pressure carbonmonoxide source. Useful pressures can be up to 138,000 kPa (20,000psig), and typically will be at least 2070 kPa (300 psig), preferably atleast 5,520 kPa (800 psig), and most preferably at least 6,900 kPa 1,000psig), and typically will range from 3450 to 34,500 kPa (500 to 5,000psig) preferably from 4485 to 20,700 kPa (650 to 3,000 psig) and mostpreferably from 4485 to 13,800 kPa (650 to 2000 psig). The carbonmonoxide pressure may be reduced by adding a catalyst such as a coppercompound. The catalyst to polymer volume ratio can range from 0.25 to 4,preferably 0.5 to 2 and most preferably 0.75 to 1.3.

Preferably, the polymer, catalyst, nucleophilic trapping agent and COare fed to the reactor in a single step. The reactor contents are thenheld for a desired amount of time under the pressure of the carbonmonoxide. The reaction time can range up to 5 hours and typically 0.5 to4 and more typically from 1 to 2 hours. The reactor contents can then bedischarged and the product which is a Koch functionalized polymercomprising either a carboxylic acid or carboxylic ester or thiol esterfunctional groups separated. Upon discharge, any unreacted CO can bevented off. Nitrogen can be used to flush the reactor and the vessel toreceive the polymer.

Depending on the particular reactants employed, the functionalizedpolymer containing reaction mixture may be a single phase, a combinationof a partitionable polymer and acid phase or an emulsion with either thepolymer phase or acid phase being the continuous phase. Upon completionof the reaction, the polymer is recovered by suitable means.

When the mixture is an emulsion, a suitable means can be used toseparate the polymer. A preferred means is the use of fluoride salts,such as sodium or ammonium fluoride in combination with an alcohol suchas butanol or methanol to neutralize the catalyst and phase separate thereaction complex. The fluoride ion helps trap the BF₃ complexed to thefunctionalized polymer and helps break emulsions generated when thecrude product is washed with water. Alcohols such as methanol andbutanol and commercial demulsifiers also help to break emulsionsespecially in combination with fluoride ions. Preferably, nucleophilictrapping agent is combined with the fluoride salt and alcohols when usedto separate polymers. The presence of the nucleophilic trapping agent asa solvent minimizes transesterification of the functionalized polymer.

Where the nucleophilic trapping agent has a pKa of less than 12 thefunctionalized polymer can be separated from the nucleophilic trappingagent and catalyst by depressurization and distillation. It has beenfound that where the nucleophilic trapping agent has lower pKa's, thecatalyst, i.e. BF₃ releases more easily from the reaction mixture.

As indicated above, polymer which has undergone the Koch reaction isalso referred to herein as functionialized polymer. Thus, afunctionalized polymer comprises molecules which have been chemicallymodified by at least one functional group so that the functionalizedpolymer is (a) capable of undergoing further chemical reaction (e.g.derivatization) or (b) has desirable properties, not otherwise possessedby the polymer alone, absent such chemical modification.

It will be observed from the discussion of formula I that the functionalgroup is characterized as being represented by the parentheticalexpression ##STR6## which expression contains the acyl group ##STR7## Itwill be understood that while the ##STR8## moiety is not added to thepolymer in the sense of being derived from a separate reactant it isstill referred to as being part of the functional group for ease ofdiscussion and description. Strictly speaking, it is the acyl groupwhich constitutes the functional group, since it is this group which isadded during chemical modification. Moreover, R¹ and R² represent groupsoriginally present on, or constituting part of, the 2 carbons bridgingthe double bond before functionalization. However, R¹ and R² wereincluded within the parenthetical so that neo acyl groups could bedifferentiated from iso acyl groups in the formula depending on theidentity of R¹ and R².

Other Functionalization Methods

While the functionalized, fractionated polymer of the present inventionis preferably prepared using the Koch reaction as heretofore described,it can also be prepared by any method suitable for introducing mono- ordicarboxylic acid producing groups (e.g., acid, ester, or anhydridegroups) into the fractionated polymer. The functionalized, fractionatedpolymer can be prepared, for example, by reacting the fractionatedpolymer with a monounsaturated carboxylic reactant, which is typically amonounsaturated monocarboxylic acid producing compound or amonounsaturated dicarboxylic acid producing compound or mixturesthereof. Preferably, the reactant comprises at least one member selectedfrom the group consisting of (i) monounsaturated C₄ to C₁₀ dicarboxylicacid wherein (a) the carboxyl groups are vicinal (i.e., located onadjacent carbon atoms) and (b) at least one, preferably both, of theadjacent carbon atoms are part of said monounsaturation; (ii)derivatives of (i) such as anhydrides or C₁ to C₅ alcohol-derived mono-or diesters of (i); (iii) monounsaturated C₃ to C₁₀ monocarboxylic acidwherein the carbon--carbon double bond is conjugated to the carboxygroups (i.e., --C═C--C(═O)--); and (iv) derivatives of (iii) such as C₁to C₅ alcohol derived monoesters of (iii).

Exemplary monounsaturated carboxylic reactants are fumaric acid,itaconic acid, maleic acid, maleic anhydride, chloromaleic anhydride,acrylic acid, methacrylic acid, and C₁ to C₄ alkyl esters of theforegoing; e.g., methyl maleate, ethyl fumarate, methyl acrylate, etc.Maleic anhydride is the preferred monounsaturated carboxylic reactant.

The fractionated polymer can be functionalized by reaction with themonounsaturated carboxylic reactant using a variety of methods. Forexample, the polymer can be first chlorinated to about 1 to 8 wt. %chlorine based on the weight of the polymer by passing chlorine throughthe polymer at a temperature of about 60° to 250° C. for about 0.5 to 10hours. The chlorinated polymer may then be reacted with sufficientmonounsaturated carboxylic reactant at about 100° to 250° C. for about0.5 to 10 hours, so the product obtained will contain the desired numberof moles of the monounsaturated carboxylic reactant per mole ofchlorinated polymer. Processes of this general type are taught in, forexample, U.S. Pat. Nos. 3,087,436, 3,172,892, and 3,272,746.Alternatively, the fractionated polymer and the monounsaturatedcarboxylic reactant can be mixed and heated while adding chlorine to thehot material. Processes of this type are disclosed in, for example, U.S.Pat. Nos. 3,215,707, 3,231,587, 3,912,764, 4,110,349 and 4,234,435.Fractionated polyisobutene (e.g., having a M_(n) of from 700 to 3,000,or more preferably from 900 to 2,500, and having a MWD of from 1.2 to2.5) is a preferred for use in these reactions.

The fractionated polymer and the monounsaturated carboxylic reactant canalso be contacted at elevated temperatures to cause a thermal enereaction to occur. Generally, the polymer and the carboxylic reactantwill be contacted with stirring and in the absence of O₂ and water(e.g., under N₂) in a carboxylic reactant to polymer mole ratio of about1:1 to 10:1 at a temperature of about 120° to 260° C. for about 1 to 20hours. Thermal ene processes are described, for example, in U.S. Pat.No. 3,361,673 and U.S. Pat. No. 3,401,118. Fractionated polyisobutene(e.g., having a M_(n) of from 700 to 3,000, or more preferably from 900to 2,500, and having a MWD of from 1.2 to 2.5) is also a preferred foruse in these reactions.

Typically, where the end use of the polymer is for making dispersant,e.g. as derivatized polymer, the polymer will possess dispersant rangemolecular weights (M_(n)) as defined hereinafter and the functionalitywill typically be significantly lower than for polymer intended formaking derivatized multifunctional V.I. improvers, where the polymerwill possess viscosity modifier range molecular weights (M_(n)) asdefined hereinafter.

Accordingly, while any effective functionality can be imparted tofunctionalized, fractionated polymer intended for subsequentderivatization, it is contemplated that such functionalities, expressedas F, for dispersant end uses, are typically not greater than about 3,preferably not greater than about 2, and typically can range from about0.5 to about 3, preferably from 0.8 to about 2.0 (e.g. 0.8 to 1).

Similarly, effective functionalities F for viscosity modifier end usesof derivatized polymer are contemplated to be typically greater thanabout 3, preferably greater than about 5, and typically will range from5 to about 10. End uses involving very high molecular weight polymerscontemplate functionalities which can range typically greater than about20, preferably greater than about 30, and most preferably greater thanabout 40, and typically can range from 20 to 60, preferably from 25 to55 and most preferably from 30 to 50.

As indicated above, the functionalization step can also be accomplishedby alkylating a hydroxy aromatic compound (e.g., phenol) with thefractionated polymer to form a polymer substituted hydroxy aromaticcompound, and wherein the resulting polymer substituted hydroxy aromaticcompound is then derivatized by reaction with an aldehyde and an amine(e.g., an alkylene polyamine) to form a Mannich base dispersant, as willbe discussed more fully below.

Derivatized Polymers

The functionalized polymer can be used as a dispersant/multifunctionalviscosity modifier if the functional group contains the requisite polargroup. The functional group can also enable the polymer to participatein a variety of chemical reactions. Derivatives of functionalizedpolymers can be formed through reaction of the functional group. Thesederivatized polymers may have the requisite properties for a variety ofuses including use as dispersants and viscosity modifiers. A derivatizedpolymer is one which has been chemically modified to perform one or morefunctions in a significantly improved way relative to theunfunctionalized polymer and/or the functionalized polymer.Representative of such functions, are dispersancy and/or viscositymodification in lubricating oil compositions.

The derivatizing compound typically contains at least one reactivederivatizing group selected to react with the functional groups of thefunctionalized polymers by various reactions. Representative of suchreactions are nucleophilic substitution, transesterification, saltformation, and the like. The derivatizing compound preferably alsocontains at least one additional group suitable for imparting thedesired properties to the derivatized polymer, e.g., polar groups. Thus,such derivatizing compounds typically will contain one or more groupsincluding amine, hydroxy, ester, amide, imide, thio, thioamido,oxazoline, or carboxylate groups or form such groups at the completionof the derivatization reaction.

The derivatized polymers include the reaction product of the aboverecited functionalized polymer with a nucleophilic reactant whichinclude amines, alcohols, amino-alcohols and mixtures thereof to formoil soluble salts, amides, oxazoline, and esters. Alternatively, thefunctionalized polymer can be reacted with basic metal salts to formmetal salts of the polymer. Preferred metals are Ca, Mg, Cu, Zn, Mo, Na,K, Mn and the like.

Functionalized, fractionated polymers prepared by reacting thefractionated polymer with a monounsaturated carboxylic reactant, whichis typically a monounsaturated monocarboxylic acid producing compound ora monounsaturated dicarboxylic acid producing compound or mixturesthereof, can be reacted with a amine or hydroxyamine or alcohol compoundaccording to methods known in the art using a variety of methods. Forexample, a polymer-substituted (e.g., polyisobutenyl-substituted)succinic anhydride or succinic acid, prepared by reaction of afractionated polymer (e.g., polyisobutene) of this invention with maleicanhydride, can be reacted with an alkylene polyamine or hydroxy amineusing the methods disclosed in U.S. Pat. Nos. 4,683,624, 4,102,798,4,116,876, 4,113,639, 5,266,223, (the disclosures which are herebyincorporated by reference in their entirety).

Mannich condensation lubricating oil dispersants can be prepared bycondensing about 1 mole of a high molecular weight hydrocarbylsubstituted hydroxy aromatic material such as mono- or polyhydroxybenzene (wherein the high molecular weight hydrocarbyl substitutentcomprises the fractionated polymer of this invention, e.g., having anumber average molecular weight of 700 or greater) with about 1 to 2.5moles of an aldehyde such as formaldehyde or paraformaldehyde and about0.5 to 2 moles polyamine as disclosed, e.g., in U.S. Pat. Nos.3,442,808; 3,649,229, 3,798,165, 5,017,299, 5,186,851, 5,382,698, and5,433,874 and U.S. Ser. No. 376,378, filed Dec. 30, 1994. and U.S. Ser.No. 322,715, filed Oct. 12, 1994 (the disclosures which are herebyincorporated by reference in their entirety).

Suitable properties sought to be imparted to the derivatized polymerinclude one or more of dispersancy, multifunctional viscositymodification, antioxidancy, friction modification, antiwear, antirust,seal swell, and the like. The preferred properties sought to be impartedto the derivatized polymer include dispersancy (both mono- andmultifunctional) and viscosity modification primarily with attendantsecondary dispersant properties. A multifunctional dispersant typicallywill function primarily as a dispersant with attendant secondaryviscosity modification.

While the Koch functionalization and derivatization techniques forpreparing multifunctional viscosity modifiers (also referred to hereinas multifunctional viscosity index improvers or MFVI) are the same asfor ashless dispersants, the functionality of a functionalized polymerintended for derivatization and eventual use as an MFVI will becontrolled to be higher than functionalized polymer intended foreventual use as a dispersant. This stems from the difference in M_(n) ofthe MFVI polymer backbone vs. the M_(n) of the dispersant polymerbackbone.

Accordingly, it is contemplated that an MFVI will be derived fromfunctionalized polymer having typically up to about one and at leastabout 0.5 functional groups, (i.e. "n" of formula (I)) for each 20,000,preferably for each 10,000, most preferably for each 5,000 M_(n)molecular weight segment in the backbone polymer.

Dispersants

Dispersants maintain oil insolubles, resulting from oil use, insuspension in the fluid thus preventing sludge flocculation andprecipitation. Suitable dispersants include, for example, dispersants ofthe ash-producing (also known as detergents) and ashless type, thelatter type being preferred. The derivatized polymer compositions of thepresent invention, can be used as ashless dispersants andmultifunctional viscosity index improvers in lubricant and fuelcompositions.

At least one functionalized polymer is mixed with at least one of amine,alcohol, including polyol, aminoalcohol, etc., to form the dispersantadditives. One class of particularly preferred dispersants are thosederived from the functionalized polymer of the present invention reactedwith (i) hydroxy compound, e.g., a polyhydric alcohol orpolyhydroxy-substituted aliphatic primary amine such as pentaerythritolor trismethylolaminomethane (ii) polyoxyalkylene polyamine, e.g.polyoxypropylene diamine, and/or (iii) polyalkylene polyamine, e.g.,polyethylene polyamine such as tetraethylene pentamine referred toherein as TEPA.

Derivatization by Amine Compounds

Useful amine compounds for derivatizing functionalized polymers compriseat least one amine and can comprise one or more additional amine orother reactive or polar groups. Where the functional group is acarboxylic acid, carboxylic ester or thiol ester, it reacts with theamine to form an amide. Preferred amines are aliphatic saturated amines.Useful amines include polyalkylene polyamines having about 2 to 60(e.g., 2 to 30), preferably 2 to 40 (e.g., 3 to 20) total carbon atomsand about 1 to 12 (e.g., 2 to 9), preferably 3 to 12 nitrogen atoms inthe molecule. Non-limiting examples of suitable amine compounds include:1,2-diaminoethane; 1,3-diaminopropane; 1,4-diaminobutane;1,6-diaminohexane; polyethylene amines such as diethylene triamine;triethylene tetramine; tetraethylene pentamine; polypropylene aminessuch as 1,2-propylene diamine, di-(1,2-propylene) triamine anddi-(1,3-propylene) triamine; N,N-dimethyl-1,3-diaminopropane;N,N'-di-(2-aminoethyl) ethylene diamine, 3-dodecylpropylamine,N-dodecyl-1,3-propane diamine; mono-, di-, and tri-tallow amines;aminomorpholines such as N-(3-aminopropyl) morpholine; and mixturesthereof.

Hydroxyamines which can be used include 2-amino-1-butanol,2-amino-2-methyl-1-propanol, p-(beta-hydroxyethyl)-aniline,2-amino-1-propanol, 3-amino-1-propanol, 2-amino-2-methyl1,3-propane-diol, 2-amino-2-ethyl-1,3-propanediol,N-(beta-hydroxypropyl)-N'-(beta-amino-ethyl)-piperazine,tris(hydroxymethyl) amino-methane (also known astrismethylolaminomethane), 2-amino-1-butanol, ethanolamine,beta-(beta-hydroxyethoxy)-ethylamine and the like. Mixtures of these orsimilar amines can also be employed.

Other useful amine compounds include: alicyclic diamines such as1,4-di(aminomethyl) cyclohexane, and heterocyclic nitrogen compoundssuch as imidazolines. Mixtures of amine compounds may advantageously beused, such as commercial mixtures of polyethylene polyamines averaging 5to 7 nitrogen atoms per molecule available under the trade names E-100(Dow Chemical) and HPA-X (Union Carbide). Useful amines also includepolyoxyalkylene polyamines. A particularly useful class of amines arethe polyamido and related amines.

The amine compound can be a heavy polyamine, which is defined herein asa mixture of higher oligomers of polyalkylene polyamines, having anaverage of at least about 7 nitrogen atoms per molecule. A preferredheavy polyamine is a mixture of polyethylene polyamines containingessentially no TEPA, at most small amounts of pentaethylene hexamine,and the balance oligomers with more than 6 nitrogens, the heavypolyamine having more branching than conventional commercial polyaminesmixtures, such as the E-100 and HPA-X mixtures noted in the precedingparagraph. A useful heavy polyamine composition is commerciallyavailable from Dow Chemical under the tradename HA-2. Useful heavypolyamines are further described in U.S. Ser. No. 273,294, filed Jul.11, 1994, herein incorporated by reference in its entirety.

Derivatization by Alcohols

The functionalized polymers of the present invention can be reacted withalcohols, e.g. to form esters. The alcohols may be aliphatic compoundssuch as monohydric and polyhydric alcohols or aromatic compounds such asphenols and naphthols. The aromatic hydroxy compounds from which theesters may be derived are illustrated by the following specificexamples: phenol, beta-naphthol, alpha-naphthol, cresol, resorcinol,catechol, etc. Phenol and alkylated phenols having up to three alkylsubstituents are preferred. The alcohols from which the esters may bederived preferably contain up to about 40 aliphatic carbon atoms. Theymay be monohydric alcohols such as methanols, ethanol, isooctanol, etc.A useful class of polyhydric alcohols are those having at least threehydroxy radicals, some of which have been esterified with amonocarboxylic acid having from about 8 to about 30 carbon atoms, suchas octanoic acid, oleic acid, stearic acid, linoleic acid, dodecanoicacid, or tall oil acid.

The esters may also be derived from unsaturated alcohols such as allylalcohol, cinnamyl alcohol, propargyl alcohol. Still another class of thealcohols capable of yielding the esters of this invention comprise theether-alcohols and amino-alcohols including, for example, theoxyalkylene-, oxyarylene-, amino-alkylene-, andamino-arylene-substituted alcohols having one or more oxyalkylene,amino-alkylene or amino-arylene oxyarylene radicals. They areexemplified by Cellosolve, carbitol, phenoxyethanol, etc.

The functionalized polymer of this invention is reacted with thealcohols according to conventional esterification, ortransesterification techniques. This normally involves heating thefunctionalized polymer with the alcohol, optionally in the presence of anormally liquid, substantially inert, organic liquid solvent/diluentand/or in the presence of esterification catalyst.

Derivatization by Reactive Metals/Metal Compounds

Useful reactive metals or reactive metal compounds are those which willform metal salts of the functionalized polymer or metal-containingcomplexes with the functionalized polymer. Metal complexes are typicallyachieved by reacting the functionalized polymers with amines and/oralcohols as discussed above and also with complex forming reactantseither during or subsequent to amination. Complex-forming metalreactants include the nitrates, nitrites, halides, carboxylates, etc.

The appropriate functionalized polymer of this invention can be reactedwith any individual derivatizing compound such as amine, alcohol,reactive metal, reactive metal compound or any combination of two ormore of any of these; that is, for example, one or more amines, one ormore alcohols, one or more reactive metals or reactive metal compounds,or a mixture of any of these. Substantially inert organic liquiddiluents may be used to facilitate mixing, temperature control, andhandling of the reaction mixture.

The reaction products produced by reacting functionalized polymer ofthis invention with derivatizing compounds such as alcohols,nitrogen-containing reactants, metal reactants, and the like will, infact, be mixtures of various reaction products. The functionalizedpolymers themselves can be mixtures of materials. While thefunctionalized polymers themselves possess some dispersantcharacteristics and can be used as dispersant additives in lubricantsand fuels, best results are achieved when at least about 30, preferably,at least about 50, most preferably 100% of the functional groups arederivatized.

Post Treatment

The functionalized and/or derivatized polymers from the presentinvention may be post-treated. U.S. Ser. No. 534,891, filed Sep. 25,1995, discloses processes for post treatment and is incorporated hereinby reference. For example, the functionalized polymers derivatized withamine compounds can be borated by treatment with a borating agent.Suitable borating agents include boron halides (e.g., boron trifluoride,boron tribromide, boron trichloride), boron acids, and simple esters ofthe boron acids (e.g., trialkyl borates containing 1 to 8 carbon alkylgroups such as methyl, ethyl, n-octyl, 2-ethylhexyl, etc.)

The boration reaction is typically carried out by adding from about 0.05to 5 wt. %, e.g. 1 to 3 wt. %, (based on the weight of theamine-containing polymeric material) of the borating agent, and heatingwith stirring at from about 90° to 250° C., preferably 135° to 190° C.,e.g., 140° to 170° C., for from about 1 to 10 hours followed by nitrogenstripping in said temperature ranges. The borating agent is preferablyboric acid which is most usually added as a slurry to the reactionmixture.

A preferred low sediment process involves borating with a particulateboric acid having a particle size distribution characterized by a φvalue of not greater than about 450. The process is described in U.S.Pat. No. 5,430,105, herein incorporated by reference.

The borated product contains at least about 0.01 up to about 10 wt. %boron based on the total weight of product, but preferably has 0.05 to 5wt. %, e.g., 0.05 to 2 wt. % boron.

Lubricating Compositions

The functionalized polymers of this invention, in addition to acting asintermediates for dispersant and MFVI manufacture, can be used asmolding release agents, molding agents, metal working lubricants, pointthickeners and the like. The primary utility for the products of theinvention, from functionalized polymer all the way through post-treatedderivatized polymer, is as additives for oleaginous compositions.

The additives of the invention may be used by incorporation into anoleaginous material such as fuels and lubricating oils. U.S. Ser. No.534,891 discloses the use of the additive derived from the presentinvention in fuels and lubricating oils and is incorporated herein byreference.

EXAMPLES

In the examples below, a significant reduction in the amount of lightester impurity generated was achieved by prestripping the polymer priorto feeding the polymer to the carbonylation reactor.

In Example 1 a polymer feed was prestripped in a short path evaporatorto eliminate light polymer (light ester precursors). The distillate wasdiscarded. This prestripped polymer was fed into the carbonylationreaction (Example A) and reacted under conditions substantially similarto polymer which was not prestripped (Example B). In Examples A and B ashort path evaporator was used to strip unreacted dichlorophenol (DCP)and other impurities from crude ester produced in a carbonylationreaction. The distillate from the evaporations of Examples A and B wascompared.

The data in Table 1 show that substantially less distillate wascollected from the stripped polymer, 15.3 wt. % (Example A) than theunstripped polymer, 21.2 wt. % (Example B).

                  TABLE 1                                                         ______________________________________                                        Evaporation Conditions                                                                   Feed rate                                                                              Temp.   Vacuum                                                                              Distillate                                                                           Residue                              Feed       Kg/Hr    °C.                                                                            mm Hg Wt. %  Kg/Hr                                ______________________________________                                        Polymer Feed                                                                             50       230     1.5   0.4    49.7                                 (Example 1)                                                                   Stripped Polymer                                                                         62       230     9.5   15.3   47.1                                 (Example A)                                                                   Unstripped Polymer                                                                       56       230     9.3   21.2   41.4                                 (Example B)                                                                   ______________________________________                                    

From mass balances, the amount of light ester was calculated for eachbatch of crude ester. Then the mass of light ester was determined perkilogram of residue product (functionalized polymer). The C₄ -C₂₀ lightesters of Example A amounted to only about 0.03 kg (mostly C₄ and C₅esters) in 8.1 kg total distillate whereas the C₄ -C₂₄ light esters ofExample B amounted to about 0.1 kg (mostly C₄ -C₆ esters) of 11.1 kgtotal distillate, as determined by mass balance data. This near order ofmagnitude difference would have a dramatic economical effect on acommercial scale operation, requiring disposal and expensive handling ofa much higher amount of light ester. The light ester otherwise rapidlybuilds up in and deteriorates the production process unless removed bymore expensive means.

There is a threefold lesser level of light ester present in the productproduced from the stripped polymer feed. Example A had only 0.79 gramslight ester per kg functionalized polymer whereas Example B had 2.91grams

                                      TABLE 2                                     __________________________________________________________________________    Molecular Weight Data by Gel Permeation Chromatography (GPC) for              Functionalized                                                                Polymer Made From Stripped and Unstripped Polymer Feed (Examples A & B)                               M.sub.w                                                                          Weight Percent Polymer                                            Temp. M.sub.n                                                                          M.sub.n                                                                          <500(1)                                                                           <1,000(1)                                                                          >20,000(2)                                __________________________________________________________________________    Unstripped Polymer (Example B)                                                               235-240° C.                                                                  3530                                                                             2.27                                                                             1.32                                                                              4.12 6.33                                      Carbonylated Product After Short                                                             235-240° C.                                                                  3415                                                                             2.35                                                                             1.5 4.81 6.63                                      Path Strip at 10 mm Hg                                                        Carbonylated Product After Short                                                             235-240° C.                                                                  3467                                                                             2.32                                                                             1.38                                                                              4.68 6.64                                      Path Strip at 1 mm Hg                                                         Stripped Polymer (Example A)                                                                 235-240° C.                                                                  3647                                                                             2.19                                                                             1.03                                                                              3.86 6.26                                      Carbonylated Product After Short                                                             235-240° C.                                                                  3643                                                                             2.26                                                                             1.04                                                                              4.23                                           Path Strip at 10 mm Hg                                                        Carbonylated Product After Short                                                             235-240° C.                                                                  3597                                                                             2.28                                                                             1.15                                                                              4.36 7.09                                      Path Strip at 1 mm Hg                                                         __________________________________________________________________________     (1)weight percent of material less than stated molecular weight               (2)weight percent of material greater than stated molecular weight       

The data in Table 2 show that the carbonylated product after short pathevaporation shows an improved quality when made from stripped polymer(Example A) when compared to product made from unstripped polymer(Example B). Product from Example A shows a directionally highermolecular weight (M_(n)), a narrower molecular weight distribution(M_(w) /M_(n)) and a lower amount of polymer less than 500 and 1,000molecular weight.

What is claimed is:
 1. A process for improving a polymer prior tocarbonylating the polymer in a Koch reaction, which comprisesfractionating the polymer to remove a light hydrocarbon fraction.
 2. Theprocess of claim 1 wherein said fractionating comprises heating thepolymer.
 3. The process of claim 1 wherein said fractionating comprisesdistilling the polymer at a temperature of about 180° to 300° C. andunder vacuum of about 1.0 to 30 mm Hg.
 4. The process of claim 1 whereinsaid fractionating comprises stripping with an inert gas.
 5. The processof claim 1 wherein said polymer is agitated.
 6. The process of any ofclaims 1 to 3 wherein said process takes place in a short pathevaporator.
 7. A functionalized hydrocarbon polymer wherein the polymerbackbone has M_(n) ≧500, functionalization is by attachment of groups ofthe formula --CO--Y--R³ wherein Y is O or S, and R³ is H, hydrocarbyl,substituted hydrocarbyl, aryl, or substituted aryl, and wherein at least50 mole % of the functional groups are attached to a tertiary carbonatom of the polymer backbone, wherein the hydrocarbon polymer isfractionated to remove light hydrocarbon from said polymer prior tofunctionalization.
 8. The polymer of claim 7 wherein said lighthydrocarbon comprises C₄ to C₂₄ hydrocarbon.
 9. The polymer of claim 7wherein said light hydrocarbon comprises light polymer.
 10. Afunctionalized hydrocarbon polymer wherein the polymer backbone hasM_(n) ≧500, the polymer backbone prior to functionalization containsless than about 1 weight percent hydrocarbon of carbon number C₂₄ andbelow, functionalization is by attachment of groups of the formula--CO--Y--R³ wherein Y is O or S, and R³ is H, hydrocarbyl, substitutedhydrocarbyl, aryl, or substituted aryl, and wherein at least 50 mole %of the functional groups are attached to a tertiary carbon atom of thepolymer backbone.